A man has been found guilty of headbutting former Manchester United midfielder Roy Keane during a “gratuitous and senseless act of violence”.

Scott Law, 43, of Waltham Abbey, Essex, attacked the football pundit following Arsenal’s 3-1 victory over Mr Keane’s former club in September last year.

The ex-Ireland captain had been working for Sky Sports at the Emirates Stadium in north London when he was assaulted, Highbury Corner Magistrates’ Court heard.

Law was handed a three-year football banning order and ordered to complete 80 hours of unpaid work. He was also told to pay legal costs of £650 plus a victim surcharge of £114.

Mr Keane was headbutted through some doors as he and fellow pundit Micah Richards were making their way to broadcast their full-time match analysis.

Law, whose seat was beneath the Sky Sports studio, claimed there had been “banter” between him and Mr Keane throughout the game.

He said it had “turned more aggressive” and when he went to use the toilet he was approached by Mr Keane.

Defence barrister Charles Sherrard KC alleged that “the red mist descended” on the former footballer after a VAR decision went against Manchester United towards the end of the match and he was taunted by home supporters.

He claimed Mr Keane swore at Law and said “say it to my face”.

Mr Keane replied to the barrister: “I said that when I was at work? Disagree.”

Mr Keane told the court he was “absolutely not expecting” the attack and said he suffered bruising on his chest and arms as a result.

Mr Richards said he was in “disbelief” at what he witnessed, and “felt sorry for Roy” who he described as a friend.

Civil engineer Law had denied a charge of common assault.

Law’s defence team said CCTV footage from inside the stadium, played in court, showed Mr Keane elbowing the defendant in the face.

More CCTV footage appeared to show Mr Law running away from the stadium on the day of the assault.

Prosecutor Simon Jones KC asked Law: “Are you seriously saying that Roy Keane ran into the top of your head?”

Law, who cried while being questioned, said: “I put my head down in a defensive manner to protect my face.”

Mr Jones said Law’s “ridiculous” defence had “changed dramatically” from a prepared statement he gave to police the day after the headbutt.

Asked about the apparent differences in this statement, Law replied: “I’d had no sleep – I was guilty by media.”

Delivering his verdict, District Judge Angus Hamilton said he believed Law had been “untruthful about what happened” during the match.

“There was no reason Mr Keane should have picked on him in particular,” he said, and added that the football pundit had been “calm and not agitated” when he left the studio.

The judge said Mr Keane’s reputation as the so-called “hard man of football” was “years ago and was confined to the football pitch”.

Kevin Christie, from the Crown Prosecution Service, said: “This gratuitous and senseless act of violence was completely unacceptable.

“When anyone attends a football match, either to work or to support a team, they should be able to feel safe and secure in that environment.”

Following the sentencing, Law said he planned to appeal against his conviction.